<p>
  添加dot
</p>
<atBadge [dot]="true" [atType]="'error'">
  消息
</atBadge>

<atBadge [dot]="true" [atType]="'error'" [show]="show">
  <button atButton (click)="show = false">隐藏红点</button>
</atBadge>
